Modular building sets are collections of interlocking pieces that can be assembled in various configurations to create structures, vehicles, or other designs. These sets often include components like blocks, panels, and connectors, allowing for creativity and flexibility in construction. Popular examples include LEGO and K'NEX, which encourage imaginative play and problem-solving skills. These building sets are suitable for all ages and can be used in educational settings to teach concepts like engineering, architecture, and spatial awareness. They promote fine motor skills and teamwork when used in group activities, making them a valuable tool for both learning and recreation.